There are at least two conditions necessary for reviving the Dinar and Dirham:
1.) Invalidation of existing “wealth” held in fiat currency.
2.) Immediate implementation of Dinars as the medium of exchange in the market.
If the introduction of gold Dinars and silver Dirhams is not accompanied by the complete erasure of existing “wealth” held in the form of fiat currency; if it allowed to exchange fiat currency for gold Dinars and silver Dirhams, the danger, of course, is that minting gold and silver coins will prove to be nothing more than a business scheme to enrich the sellers of the coins.
If people cannot begin immediately to trade Dinars and Dirhams for goods in the market, their coins will essentially be no different than any gold jewelry they may already own; it will have value measured in fiat currency, but no value as a currency of trade.